This is an early stage in traditional wrought iron production. After a puddle ball is shingled into a bloom, it is passed through roughing rolls to create a thick, coarse bar. These bars are heavily slagged and not ready for final use, so they are cut, stacked, reheated, and rolled again to produce refined merchant iron.
Heard on the job
Stack the mill bar by the reheating furnace so the crew can prep the next batch of merchant iron.
Insider tip
You will mostly see this term in texts about traditional wrought iron mills.